Hello all, I have encountered a problem that I have not heard of anyone else experiencing. I have been shooting PC'd bullets for about 2.5 months, and have had great results with them in several competitions so far. I am shooting them from a G19 with a lone wolf barrel. The problem I have encountered is that the rifling just after my chamber seems to be eroding. At first I thought this was just a large amount of freebore that I hadn't noticed yet in any of my previous cleaning sessions, but after several other shooting and cleaning sessions, it appears that the rifling has eroded more. I have a few pictures of what Im talking about. I have compared my barrel to several other glock barrels, and mine really does appear to have eroded a lot. On my last range session, last week, I noticed that a few rounds had started keyholing, this is something that I have not had happen to me yet with my loads in any of my 9mm pistols. I haven't noticed any rifling erosion in any of my other 9mm's, but admittedly I shoot my Glock A LOT more. I am not ready to say that the PC'd bullets have caused this or not, but I wanted to know if anyone else had experienced anything similar to this in any pistol EVER. Any help with this would be appreciated.
This is a picture from the chamber looking out to the Muzzle. You can see that after the end of the chamber that the case mouth indexes on, there is a very LARGE amount of freebore before the bullet starts to make contact with the rifling.
This is a picture from the Muzzle looking in toward the chamber. The erosion can be seen here too.